An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Microgel suspensions have garnered significant interest in fundamental research due to their phase transition between liquid-like to paste-like behaviors stemming from tunable interparticle and particle–solvent interactions. Particularly, stimuli-responsive microgels undergo faster volume changes in response to external stimuli in comparison to their bulk counterparts, while maintaining their structural integrity. Here, concentrated and diluted suspensions of poly(N-isopropylacrylamide) (PNIPAm) microgels are dispersed to different packing fractions in water for the characterizations of temperature-responsive rheological responses. In the intrinsic volume phase transition (VPT), polymer chains collapse, and microgels shrink to smaller sizes. Additionally, the intermicrogel and microgel–solvent interactions vary in VPT, which results in microgel clusters that significantly affect the linear shear moduli of suspensions. The effect of the temperature ramp rate of PNIPAm microgel suspensions on rheological responses is characterized. Moreover, the effect of the mass fraction of microgels on the relative viscosity of dilute microgel suspensions is investigated. These results shed light on understanding the heating and cooling rate-dependent temperature responsiveness of PNIPAm microgel suspensions, establishing pathways to regulate the rheological characteristics in temperature-responsive microgel-based platforms. Therefore, this work envisions technological advancements in different fields such as drug delivery, tissue engineering, and diagnostic tools.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
In developing a cluster-nanocarrier design, as a magnetic resonance imaging contrast agent, we have investigated the enhanced relaxivity of a manganese and iron-oxo cluster grafted within a porous polystyrene nanobead with increased relaxivity due to a higher surface area. The synthesis of the cluster-nanocarrier for the cluster Mn8Fe4O12(O2CC6H4CH═CH2)16(H2O)4, cross-linked with polystyrene (the nanocarrier), under miniemulsion conditions is described. By including a branched hydrophobe, iso-octane, the resulting nanobeads are porous and ∼70 nm in diameter. The increased surface area of the nanobeads compared to nonporous nanobeads leads to an enhancement in relaxivity; r1 increases from 3.8 to 5.2 ± 0.1 mM–1 s–1, and r2 increases from 11.9 to 50.1 ± 4.8 mM–1 s–1, at 9.4 teslas, strengthening the potential for T1 and T2 imaging. Several metrics were used to assess stability, and the porosity produced no reduction in metal stability. Synchrotron X-ray fluorescence microscopy was used to demonstrate that the nanobeads remain intact in vivo. In depth, physicochemical characteristics were determined, including extensive pharmacokinetics, in vivo imaging, and systemic biodistribution analysis.
Welcome to the 2021 Virtual Cannabis Research Conference! This three-day, comprehensive conference explores new cannabis research frontiers in medicine, science, and society. Visit the CRC Virtual Exhibit Hall, between 8:00 am - 4:30 pm MT and meet the exhibitors. | Turn your camera & mic on and visit the CRC Virtual Networking Lounge. Mingle with other conference attendees around the clock. Visit: [Conference Program Book](https://online.fliphtml5.com/wowbk/dwbj/#p=1) | [Virtual Exhibit Hall](https://exhibithall.cannabisresearchconference.net/live/index.html) | [Virtual Networking Lounge](https://www.wonder.me/r?id=56fa86df-578b-4e0e-9ef5-064766ae5161) THE TIMES LISTED BELOW ARE IN YOUR TIME ZONE. PLEASE REFER TO THE PROGRAM BOOK FOR THE MOUNTAIN TIME ZONE.
There is an increasing need for gadolinium-free magnetic resonance imaging (MRI) contrast agents, particularly for patients suffering from chronic kidney disease. Using a cluster-nanocarrier combination, we have identified a novel approach to the design of biomedical nanomaterials and report here the criteria for the cluster and the nanocarrier and the advantages of this combination. We have investigated the relaxivity of the following manganese oxo clusters: the parent cluster Mn3(O2CCH3)6(Bpy)2 (1) where Bpy = 2,2'-bipyridine and three new analogs, Mn3(O2CC6H4CH═CH2)6(Bpy)2 (2), Mn3(O2CC(CH3)═CH2)6(Bpy)2 (3), and Mn3O(O2CCH3)6(Pyr)2 (4) where Pyr = pyridine. The parent cluster, Mn3(O2CCH3)6(Bpy)2 (1), had impressive relaxivity ( r1 = 6.9 mM-1 s-1, r2 = 125 mM-1 s-1) and was found to be the most amenable for the synthesis of cluster-nanocarrier nanobeads. Using the inverse miniemulsion polymerization technique (1) in combination with the hydrophilic monomer acrylamide, we synthesized nanobeads (∼125 nm diameter) with homogeneously dispersed clusters within the polyacrylamide matrix (termed Mn3Bpy-PAm). The nanobeads were surface-modified by co-polymerization with an amine-functionalized monomer. This enabled various postsynthetic modifications, for example, to attach a near-IR dye, Cyanine7, as well as a targeting agent. When evaluated as a potential multimodal MRI contrast agent, high relaxivity and contrast were observed with r1 = 54.4 mM-1 s-1 and r2 = 144 mM-1 s-1, surpassing T1 relaxivity of clinically used Gd-DTPA chelates as well as comparable T2 relaxivity to iron oxide microspheres. Physicochemical properties, cellular uptake, and impacts on cell viability were also investigated.
